In my fantasy setting which I have been building, then there's a planet neighboring the main planet of my setting. I've taken to calling it Kazimar. On it, then there are two intelligent races that inhabit it: The lowland Primulis and the mountain-dwelling Axulis.
The Primulis specifically have skulls with multiple horny protrusions, and lack mouths. They eat and communicate with their horns, which can be used to more easily manipulate magic to transfer nutrients from food and water directly into the body, and to send telepathic messages to one another, registering on their auditory senses in the form of words, as an adapted communication in order to speak with their highland counterparts, who need to communicate verbally through physical sound.
But this begs the question for me: What would their written language be like?
Would it be significantly different to written language in our world? Or would it still have similarities?
[EDIT] The materials they can use for writing trend more towards the harder substances, such as stones and metals. Carved using their magically infused horns.